JP2007022883A - Inorganic formed body provided with anti-bacterial/anti-fungal deodorizing function, and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an high performance inorganic formed body provided with both of a high anti-bacterial/anti-fungal deodorizing property and humidity control property, and to provide a method of manufacturing the inorganic formed body. <P>SOLUTION: The inorganic formed body consists essentially of calcium carbonate and amorphous silica originating in a calcium silicate compound, has ≥80 m<SP>2</SP>/g and ≤250 m<SP>2</SP>/g specific surface area measured by a gaseous nitrogen adsorption method and a pore diameter distribution having peaks respectively in a region of ≤5 nm diameter and a region of ≥50 nm and ≤1,000 nm diameter and is formed by supporting an anti-bacterial/anti-fungal deodorizing metal ion on calcium carbonate or amorphous silica. The inorganic formed body is manufactured by bringing the anti-bacterial/anti-fungal deodorizing metal ion into contact with raw material powder consisting essentially of calcium silicate to replace calcium ion by the anti-bacterial/anti-fungal deodorizing metal ion and forming and aging (carbonation treatment) under a carbon dioxide atmosphere. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an inorganic molded body having an antibacterial and antifungal deodorizing function and a method for producing the same.

  Since the humidity-conditioning building material absorbs moisture in the air, it is desirable that the humidity-controlling material does not easily propagate microorganisms such as bacteria and mold. Moreover, since it is porous, it is expected to absorb malodorous components and contribute to prevention of sick house syndrome and the like.

Conventionally, as humidity control building materials with antibacterial, antifungal and deodorant performances, zeolites carrying metal ions mixed with cement and water-soluble resin (Patent Document 1), zeolites carrying metal ions Oyster shell powder and sepiolite mixed and baked (Patent Document 2) have been developed.
JP-A-3-109244 JP-A-8-310881

  However, the concrete material as disclosed in Patent Document 1 generates outgas such as ammonia, and thus is not suitable for application to a place sensitive to the influence of outgas such as a museum or a semiconductor factory. In addition, since the cement itself is poor in humidity control properties, if the zeolite content is increased in order to ensure the required humidity control performance, the strength of the material may decrease due to a relative decrease in the cement content.

  In addition, in a sintered body that undergoes a high-temperature firing process as in Patent Document 2, when heating is performed at a high temperature at which sintering proceeds sufficiently, melting / evaporation of the supported metal, oxidation, The chemical reaction or the like may impair the antibacterial and antifungal deodorizing performance of the metal, or may change the pore structure of the carrier and impair the humidity control performance. On the other hand, if firing is performed at such a low temperature that metal melting and chemical reaction do not occur, sintering may not proceed sufficiently and sufficient strength may not be obtained.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide an excellent inorganic molded body having high antibacterial properties, antifungal properties, deodorizing performance and humidity control properties, and a method for producing the same. .

  The inventors of the present invention have found that a carbonated cured product obtained by carbonating a calcium silicate compound exhibits excellent humidity control performance, and have obtained patents (for example, Patent No. 3065607, Patent No. 3212588). issue). In the course of earnestly researching to develop an excellent inorganic molded article having high antibacterial, antifungal, deodorant performance and humidity control property, and a method for producing the same, the carbonic acid cured body has antibacterial, antifungal, When a metal having deodorant performance is supported, extremely excellent antibacterial, antifungal, and deodorant performance is exhibited, and the properties such as humidity control performance and strength inherent to the carbonic acid cured body are hardly impaired. I found.

The mechanism of antibacterial and antifungal action is as follows. When fungi or mold adhere to the surface of the carbonic acid cured body or enter the pores, the antibacterial and antifungal deodorant metal ions bind to the fungus and mold cell membranes and membrane proteins, enzymes, and DNA, damaging these three-dimensional structures. Is considered to cause functional impairment.
Moreover, the mechanism of the deodorizing action is as follows. Antibacterial and antifungal deodorant metal ions are highly reducible and exhibit high reactivity with sulfides and organic substances (especially thiol groups, carboxyl groups, phenol hydroxyl groups, and sulfone groups) to alter odor components.
In particular, according to the present inventors' previous research, a carbonized cured body mainly composed of calcium carbonate and amorphous silica obtained by carbonating a calcium silicate compound has a diameter in the pore size distribution. It is known to have a characteristic macro / meso binary pore structure in which peaks are shown in a micro to meso region of 5 nm or less and a macro region of a diameter of 50 nm or more and 1000 nm or less. When an inorganic molded body having such a pore structure is loaded with a metal having antibacterial, antifungal, and deodorizing performance, extremely excellent deodorizing performance is exhibited. The mechanism is considered as follows.

  When an inorganic molded body carrying a metal is placed in an atmosphere containing an odor component, the odor component enters the pore and is adsorbed on the inner surface of the pore, and receives the deodorizing action of the metal carried thereon. Here, the macropores having a diameter of 50 nm to 1000 nm have an effect of improving the responsiveness of increasing the opening area on the surface of the inorganic molded body and contributing to prompt incorporation of the odorous component into the pores. On the other hand, the micro to mesopores having a diameter of 5 nm or less have an effect of increasing the adsorption amount of the odor component to the inorganic molded body, which increases the specific surface area of the carbonized cured body and contributes to increase the contact area with the odor component. .

That is, when the inorganic molded body has only macropores, the odorous component can be quickly taken into the pores due to the large opening area on the surface, but the specific surface area compared to the inorganic molded body containing micro to mesopores. Therefore, the amount of odor components that can be adsorbed per unit volume is relatively small. On the other hand, an inorganic molded body having only micro to mesopores has a large specific surface area, so the amount of odorous components that can be adsorbed per unit volume is theoretically large, but in reality the opening area is small. The odor component does not readily penetrate into the pores, and the adsorption rate is particularly low in the initial stage. On the other hand, in the carbonic acid cured body having both macropores and micro to mesopores, first, the surface opening area can be secured by the presence of the macropores, so that the odor component is quickly taken into the pores. . And the taken-in odor component is adsorbed on the inner surface of the pores and is subjected to the deodorizing action of the metal ions carried thereon. At this time, a large number of micro to mesopores are opened on the inner surface of the macropores, and the specific surface area is increased, so that the contact area between the odorous component and the supported metal is increased, and per unit time. An increase in throughput can be expected. In this way, the synergistic effect of improved responsiveness by macropores and increased adsorption area by micro to mesopores significantly improves deodorization performance compared to inorganic molded bodies having only macropores or only micro to mesopores. It can be made.
The present invention has been made based on such novel findings.

That is, the present invention is an inorganic molded body mainly composed of calcium carbonate and amorphous silica originating from a calcium silicate compound, and has a specific surface area of 80 m ² / g or more measured by a nitrogen gas adsorption method. 250 m ² / g or less, having a pore size distribution in which a peak exists in a region having a diameter of 5 nm or less and a region having a diameter of 50 nm or more and 1000 nm or less, and the antibacterial and antifungal properties of the calcium carbonate or amorphous silica It is characterized in that odorous metal ions are supported.

  Here, “amorphous silica originating from a calcium silicate compound” is amorphous silica obtained from a calcium silicate compound by a carbonation reaction or the like, and the shape of the original calcium silicate compound is almost the same. This is what is being maintained. For example, amorphous silica obtained by carbonating tobermorite has a hexagonal plate shape or an elongated plate shape like a bamboo leaf, and is obtained from low crystalline calcium silicate hydrate (CSH). Silica is shaped like a crumpled aluminum foil, and amorphous silica obtained from zonotlite has a needle shape. Whether the amorphous silica originates from a calcium silicate compound is determined by observing the obtained amorphous silica with a scanning electron microscope (SEM) or a transmission electron microscope (TEM). It can be known by confirming whether or not the shape of the calcium compound exists.

A method for producing such an inorganic molded body is, for example, as follows. First, an aqueous solution containing antibacterial and antifungal deodorant metal ions was mixed with powder containing a calcium silicate compound as a main component, and at least a part of calcium ions contained in calcium silicate was replaced with metal ions. A metal-supported powder is obtained. Thereafter, this metal-supported powder is added alone or added to calcium silicate powder not supporting metal ions, kneaded with water, and molded and carbonized to obtain a molded body.
That is, when an aqueous solution containing a metal ion having antibacterial, antifungal, and deodorizing performance is brought into contact with the calcium silicate compound, the calcium ion contained in the calcium silicate compound is replaced with the metal ion. When this calcium silicate compound is molded and carbonated, a carbonated cured product in which metal ions are supported in the pores of amorphous silica can be obtained.
In addition, when preparing a metal carrying | support powder, you may wash-filter as needed and wash away an excess component.

  Also, when preparing the metal-supported powder, instead of the powder containing the calcium silicate compound as the main component, a powder containing calcium carbonate and amorphous silica originating from the calcium silicate compound as the main component is used. You may do it. In this case, since the obtained metal-supported powder itself does not have hydraulic and carbonic curability, the metal-supported powder is added to the calcium silicate powder, kneaded with water, and molded and carbonized. A molded body is obtained.

According to the inorganic molded body of the present invention, a carbonic acid cured product obtained by carbonizing a calcium silicate compound carries a metal having antibacterial, antifungal, and deodorizing effects, thereby providing high antibacterial properties. It is possible to provide an excellent inorganic molded article having antifungal, deodorizing performance and humidity control properties.
In particular, since this type of carbonic acid cured product has a macro / meso binary pore structure, it exhibits an excellent deodorizing action. That is, since the opening area of the surface can be secured due to the presence of the macropores, the odor component is quickly taken into the pores of the inorganic molded body. And the taken-in odor component receives the deodorizing effect | action of the metal ion currently carry | supported. At this time, a large number of micro to mesopores are opened on the inner surface of the macropores, and the specific surface area is increased, so that the contact area between the odorous component and the supported metal is increased, and per unit time. An increase in throughput can be expected. Thus, the synergistic effect of improved responsiveness by macropores and increased adsorption area by micro to mesopores provides superior deodorizing performance compared to inorganic molded bodies having only macropores or only micro to mesopores. It can be demonstrated.
In addition, since the base material is a neutral material mainly composed of calcium carbonate and amorphous silica, it is easy to handle and may release components that adversely affect the surrounding environment such as concrete. Absent. Furthermore, since the raw material calcium silicate compound is inexpensive, an excellent antibacterial and antifungal deodorizing inorganic molded body can be provided at a low cost.
Furthermore, since the antibacterial and antifungal deodorizing metal is directly supported in the structure of calcium carbonate or amorphous silica constituting the molded body, the molded body is formed by the presence of a support material different from the components constituting the molded body. There is no risk of damaging the strength, humidity control performance, etc.

Further, according to the method for producing an inorganic molded body of the present invention, the calcium ion in the raw material powder or the carrier powder added to the raw material powder is replaced by an antibacterial antifungal deodorant metal by ion exchange, By subjecting to a carbonation treatment, the antibacterial and antifungal deodorant metal is directly supported in the structure of calcium carbonate or amorphous silica constituting the molded body. For this reason, unlike the case where a metal is simply adhered to the inner surface of the pore, elution of metal ions is suppressed. Thereby, antibacterial, antifungal and deodorizing actions can be maintained over a long period of time, and contamination of the surrounding environment by the eluted metal ions can be prevented. Further, the metal can be more uniformly dispersed in the molded body.
In addition, since a relatively low temperature process called carbonation treatment is adopted, the range of the antibacterial, antifungal, deodorant metal that is supported, melting, chemical reaction, etc. does not occur compared to methods that undergo high temperature processes such as firing. With this, the curing reaction can be advanced to form a molded article having sufficient strength.

1. Inorganic molded body The inorganic molded body of the present invention is an inorganic molded body mainly composed of calcium carbonate and amorphous silica originating from a calcium silicate compound, and has a specific surface area measured by a nitrogen gas adsorption method. 80 m ² / g or more and 250 m ² / g or less, having a pore size distribution in which a peak exists in a region having a diameter of 5 nm or less and a region having a diameter of 50 nm or more and 1000 nm or less, and is antibacterial to calcium carbonate or amorphous silica Antifungal deodorant metal ions are supported.

The inorganic molded body of the present invention is a carbonated cured body obtained by carbonizing a calcium silicate compound, and carries a metal having antibacterial, antifungal and deodorizing actions. Such an inorganic molded body has high antibacterial, antifungal, deodorizing performance and humidity control.
In particular, since this type of carbonic acid cured product has a macro / meso binary pore structure, the deodorizing action is particularly improved. In other words, macropores with a diameter of 50 nm or more play a role of allowing odorous components to rapidly penetrate into the pores of the inorganic molded body, and mesopores with a diameter of 2 to 50 nm or micropores with a diameter of 2 nm or less adsorb odorous components. It plays a role in increasing the area.

  In the present invention, the antibacterial and antifungal deodorant metal is not particularly limited as long as it is a metal having antibacterial, antifungal, and deodorant properties, and examples thereof include silver, copper, and zinc. These metals may be used alone or in combination of two or more. Furthermore, silver is most preferable from the viewpoint of safety. The support ratio of the antibacterial and antifungal metal to the inorganic molded body is preferably 0.005 wt% or more and 0.5 wt% or less with respect to the total weight of the inorganic molded body.

2. 2. Manufacturing method of inorganic molded body 2.1 Material 1) Raw material powder As the raw material powder mainly composed of calcium silicate compound, it is preferable to use a material mainly composed of tobermorite. Calcium silicate is converted into calcium carbonate and amorphous silica by carbonation. In particular, in tobermorite, vaterite that is very fine particles is produced together with the most stable calcite as calcium carbonate. Vaterite is a fine product and a very large specific surface area is realized by this and amorphous silica having fine pores. Thereby, the obtained inorganic molded body has a characteristic pore size distribution of having macropores and micro to mesopores, and exhibits excellent antibacterial and antifungal deodorizing performance. As the calcium silicate raw material, for example, purely synthesized tobermorite can be used, but it is particularly preferable to use lightweight aerated concrete (ALC) powder from the viewpoint of recycling and stable quality.

  The particle size of the raw material powder is preferably 0.1 μm or more and 1 mm or less in view of the efficiency of the manufacturing process and the influence on the physical properties of the obtained inorganic molded body. When the particle diameter exceeds 1 mm, it takes a long time for metal ions or carbon dioxide gas to penetrate into the particles in the ion exchange or carbonation treatment described later. On the other hand, when the thickness is 0.1 μm or less, cleaning filtration becomes difficult when a cleaning process is present in the process.

2) Carrier powder As the carrier powder, a powder mainly composed of the same kind of calcium silicate compound as the raw material powder can be used.
Further, a powder in which a calcium silicate compound is carbonated in advance, that is, a powder mainly composed of calcium carbonate and amorphous silica originating from the calcium silicate compound may be used. In particular, from the viewpoint of recycling, it is preferable to use the waste material of the inorganic molded body of the present invention, or the waste material of the calcium silicate building material that has been carbonated over time with carbon dioxide in the air during use.

3) Aqueous solution containing antibacterial and antifungal deodorant metal ions As an aqueous solution containing the antibacterial and antifungal deodorant metal ions, an aqueous solution of a salt containing the desired antibacterial and antifungal deodorant metal ions can be used. . Examples of the salt containing a metal ion include silver nitrate, silver sulfate, silver perchlorate, silver acetate, diammine silver nitrate, and diammine silver sulfate when the target metal is silver, and the target metal is copper. In some cases, copper nitrate, copper sulfate, copper perchlorate, copper acetate, potassium tetracyanocuprate, etc. If the target metal is zinc, zinc (II) nitrate, zinc sulfate, perchloric acid Zinc, zinc thiocyanate, zinc acetate and the like can be used.
Moreover, it is preferable to adjust pH of aqueous solution to 3-10, and it is more preferable to adjust 5-7. By adjusting in this way, it can suppress that a metal oxide precipitates on the surface or pore inside of a calcium silicate compound.

2.2 Manufacturing Method Hereinafter, the method for manufacturing the inorganic molded body as described above will be described with three examples.

2.2.1 First manufacturing method (corresponding to the invention of claim 5)
In FIG. 1, the process drawing of the 1st manufacturing method for obtaining an inorganic molded object was shown.
First, an aqueous solution containing antibacterial, antifungal and deodorant metal ions is added to and mixed with raw material powder mainly composed of calcium silicate (kneading step). Mixing can be performed using a normal mixer or the like provided with a stirring member such as an agitator inside the stirring vessel. In this step, the moisture content of the raw material powder is adjusted to such an extent that the molding and carbonation treatment described later can be performed smoothly, and at least a part of the calcium ions contained in the calcium silicate is antibacterial and antifungal. Substitution by cation exchange with deodorant metal ions.

An appropriate concentration of the metal ions contained in the aqueous solution is 0.01% by weight or more and 5.0% by weight or less. At this time, the appropriate addition ratio of the aqueous solution to the raw material powder is preferably 10 to 50% by weight with respect to the dry weight of the raw material powder.
Although there is a slight weight fluctuation due to carbonation, the metal loading in the obtained molded product is almost correlated with the amount of metal ions added to the raw material powder, so that the above metal ion concentration and addition rate can be obtained. The metal loading in the molded body is minimum (when the metal ion concentration is 0.01% by weight and the addition rate is 10% by weight) and is about 0.001% by weight and the maximum (the metal ion concentration is 5.0% by weight, the addition rate is 50% by weight). %) Is about 2.5% by weight. Furthermore, since the more preferable metal loading is 0.005 wt% or more and 0.5 wt%, it is preferable to adjust the metal ion concentration and the addition ratio so as to fall within this range.
Further, when the addition ratio of the aqueous solution is 10% by weight or less, the water content is too small so that the strength of the molded product cannot be obtained in press molding, and the carbonation reaction does not proceed sufficiently in the carbonation step. On the other hand, if the addition ratio is 50% by weight or more, it takes a long time to press-mold because there is too much moisture, and the calcium component and metal ions flow out or cause delamination in the molded body because it becomes a dewatering press. It becomes.

  In this kneading step, a calcium salt (for example, calcium nitrate when the metal salt is nitrate) is generated by the reaction between calcium ions contained in the raw material powder and the metal salt in the aqueous solution. Since this calcium salt is considered to have various effects on the inorganic molded body formed according to the type and nature of the calcium salt, the type of metal salt used, the concentration of the aqueous solution, It is preferable to determine the addition amount and the like.

  When mixing is completed, the obtained kneaded material is molded (molding process). There is no restriction | limiting in particular in a shaping | molding method, For example, it can carry out by the uniaxial press molding method. The molding pressure is preferably 5 to 40 MPa. If the pressure is less than 5 MPa, the strength of the molded product cannot be obtained, the subsequent handling becomes difficult, and the strength of the molded product after the carbonation treatment is not sufficient. On the other hand, if it exceeds 40 MPa, a large-scale press is required, which increases the manufacturing cost, and delamination tends to occur in the molded body.

  Next, the obtained molded product is cured under a carbon dioxide atmosphere (carbonation treatment step). The carbonation treatment is performed by bringing the molded product into contact with carbon dioxide gas in a curing pot, for example, to cause a carbonation reaction.

  Here, as the carbon dioxide gas, carbon dioxide having a purity of 100% may be used, or a mixed gas mixed with another gas may be used. Specifically, commercially available liquefied carbon dioxide or dry ice vaporized, combustion gas, exhaust gas, or the like can be used. When a mixed gas is used, the higher the carbon dioxide concentration, the faster the reaction proceeds. Specifically, the carbon dioxide concentration is preferably 3% or more, and more preferably 30% or more. If the carbon dioxide concentration is 3% or less, the reaction rate becomes too slow, which is not industrially appropriate. In the case of using a mixed gas, the other gas to be mixed is preferably an inert gas such as nitrogen, oxygen or the like. When exhaust gas is used, it is preferable to use one that has been subjected to desulfurization, denitration, and dust collection.

  Although the reaction temperature is not particularly limited, it is preferable that the water content in the molded article promotes the carbonation reaction, that is, a state where water is present in the molded article, that is, 0 ° C. or higher and 100 ° C. or lower. In particular, the carbonation reaction is promoted when the reaction temperature is 30 to 80 ° C., but the carbonation reaction is exothermic, which increases the temperature in the kettle. It is desirable that the temperature be approximately 60 ° C. or lower. In addition, the pressure during carbonic acid curing greatly affects the reaction rate. The higher the pressure, the more the reaction is promoted.

  Furthermore, in order to efficiently perform the carbonation reaction, a vacuum process is performed in which the inside of the kettle is evacuated in advance prior to the inflow of carbon dioxide gas into the kettle. A method of flowing a carbon dioxide gas having a concentration into the kettle can be applied.

  By this carbonation reaction, the calcium component in calcium silicate escapes as calcium carbonate. Calcium carbonate produces not only the most stable calcite but also fine vaterite. In addition, the portion of calcium silicate where calcium ions were present becomes fine voids, and amorphous silica having many pores can be formed while maintaining the original calcium silicate skeleton. At this time, metal ions substituted for calcium ions in the kneading process partly escape with the calcium component, but most remain in the amorphous silica. This has a characteristic macro / meso binary pore structure showing a peak in a micro to meso region having a diameter of 5 nm or less and a macro region having a diameter of 50 nm or more and 1000 nm or less in the pore size distribution, and calcium carbonate or An inorganic molded body is obtained in which ions of antibacterial, antifungal and deodorant metal are supported on amorphous silica.

In addition, this carbonation process advances at normal temperature to about 100 degreeC. Therefore, unlike methods that go through high-temperature processes such as firing, the curing reaction proceeds sufficiently at low temperatures that do not cause melting, chemical reaction, etc. of the supported antibacterial and antifungal deodorant metals, and sufficient strength as building materials A molded body having can be formed.
The obtained inorganic molded body is dried and then shipped as a product.

  This first manufacturing method is the simplest process, and can be carried out using the existing carbonated cured body production equipment as it is, so that an inorganic molded body can be provided at a low cost.

2.2.2 Second manufacturing method (corresponding to the invention of claim 7)
In FIG. 2, the process drawing of the 2nd manufacturing method for obtaining an inorganic molded object was shown.
First, water is added to the raw material powder to form a slurry, and an aqueous solution containing antibacterial, antifungal and deodorant metal ions is added to the slurry and stirred. In this step, at least a part of calcium ions contained in the calcium silicate is replaced by cation exchange with ions of the antibacterial and antifungal deodorant metal (ion exchange step). Here, the metal ions can be uniformly dispersed in the raw material powder by performing ion exchange in a state where the raw material powder is made into a slurry having high fluidity.

  The slurry can be stirred batchwise or continuously using, for example, an ordinary mixer equipped with a stirring member such as an agitator inside the stirring vessel. The mixing temperature is preferably 10 ° C. or higher and 80 ° C. or lower. The mixing time is preferably 3 hours or more and 24 hours or less. In addition, it is preferable to adjust suitably the metal ion density | concentration in aqueous solution so that the metal supporting rate in the inorganic molded object finally obtained may be 0.005-0.5 weight%.

  When the ion exchange is completed, the obtained metal-supported raw material powder is washed with water while suction filtration to remove excess metal salt and calcium salt generated by the reaction between the metal salt and calcium (washing step). For example, when the antibacterial and antifungal deodorant metal ions are silver ions, it is preferable to carry out the washing sufficiently until, for example, hydrochloric acid or a sodium chloride aqueous solution is dropped into the filtrate so that the cloudiness due to silver chloride does not occur.

  When the washing is completed, the metal-supporting raw material powder is dried until the water content becomes such that the molding and carbonation treatment described later can be performed smoothly (moisture content adjusting step). Drying is preferably performed at 105 ° C. to 110 ° C. under normal pressure, or 70 ° C. to 90 ° C. under reduced pressure (1 to 30 Torr).

  When the moisture content adjusting step is completed, the metal-supported raw material powder is molded and carbonized in the same manner as in the first manufacturing method described above, and then dried to obtain an inorganic molded body.

  In this method, in the ion exchange step, an aqueous solution containing antibacterial, antifungal and deodorant metal ions is added to the raw material powder to form a highly fluid slurry, so that the metal ions can be uniformly dispersed in the slurry. Ion exchange can be performed uniformly over the entire raw material powder. Therefore, the ions of the antibacterial, antifungal and deodorant metal can be uniformly supported throughout the inorganic molded body.

  In addition, since the metal-supported raw material powder after ion exchange is washed and molded and subjected to a carbonation step, the effects of by-products such as calcium salts and residual metal salts can be eliminated, and the quality is stable. An inorganic molded body can be supplied.

2.2.3 Third manufacturing method (corresponding to inventions of claims 8 and 9)
In FIG. 3, the process drawing of the 3rd manufacturing method for obtaining an inorganic molded object was shown.
First, water is added to the carrier powder to form a slurry, and an aqueous solution containing antibacterial, antifungal and deodorant metal ions is added to the slurry and stirred. In this step, at least a part of calcium ions contained in the calcium silicate is replaced by cation exchange with ions of the antibacterial and antifungal deodorant metal, and a metal-supported powder is obtained (ion exchange step). Stirring can be performed under the same conditions as in the ion exchange step of the second production method using an ordinary mixer or the like.

  When the ion exchange is completed, the obtained metal-supported powder is washed and dried (washing and drying step). Washing and drying may be performed in the same manner as in the second manufacturing method described above. However, the water content of the metal-supported powder need not be particularly adjusted in this step.

  Next, the obtained metal-supported powder is added to a raw material powder containing a calcium silicate compound as a main component, and water is added and mixed (kneading step). Mixing can be performed under the same conditions as in the kneading step of the first production method described above using an ordinary mixer or the like. The amount of the metal-supported powder added to the raw material powder may be determined in consideration of the amount of metal ions supported in the metal-supported powder and the target metal ion support rate in the final inorganic compact.

  When the kneading step is completed, the obtained kneaded product is molded and carbonized in the same manner as in the first production method described above, and then dried to obtain an inorganic molded body.

  In this method, metal is supported on a small amount of support powder in advance to prepare a metal-supported powder, and this is mixed with the raw material powder. Therefore, a large amount of water is used, and the equipment tends to be large in size. The process / cleaning process can be reduced in scale as compared with the second manufacturing method. Thereby, the complexity of the manufacturing process and the increase in cost can be avoided. In addition, if the amount of metal ions supported on the metal-supported powder is measured after the cleaning / drying process is completed, and the amount of metal-supported powder added to the raw material powder is determined based on the measured value, the metal in the final inorganic compact The ion loading rate can be reliably controlled.

3. Effects When the inorganic molded body as described above is used as a humidity-controllable building material, for example, in the interior of a building, the object to be treated such as bacteria, mold, and odor components in the atmosphere is in the surface or pores of the inorganic molded body. Adhered to or adsorbed on metal, it receives metal antibacterial, antifungal and deodorizing effects.
In particular, an excellent deodorizing action is exhibited by the macro / meso binary pore structure of the inorganic molded body. That is, since the opening area of the surface is ensured by the presence of the macropores, the odor component is quickly taken into the pores of the inorganic molded body. And the taken-in odor component receives the deodorizing effect | action of the metal ion currently carry | supported. At this time, a large number of micro to mesopores are opened on the inner surface of the macropores, and the specific surface area is increased, so that the contact area between the supported metal and the odor component is increased, and treatment per unit time An increase in the amount can be expected. In this way, the synergistic effect of improved responsiveness by macropores and increased adsorption area by micro to mesopores significantly improves deodorization performance compared to inorganic molded bodies having only macropores or only micro to mesopores. Can be made.

  In addition, since the base material is a neutral material mainly composed of calcium carbonate and amorphous silica, it is easy to handle and may release components that adversely affect the surrounding environment such as concrete. Absent. Furthermore, since the raw material calcium silicate compound is inexpensive, an excellent antibacterial and antifungal deodorizing inorganic molded body can be provided at a low cost.

  Furthermore, since the antibacterial and antifungal deodorizing metal is directly supported in the structure of calcium carbonate or amorphous silica constituting the molded body, the molded body is formed by the presence of a support material different from the components constituting the molded body. There is no risk of damaging the strength, humidity control performance, etc.

  Hereinafter, the present invention will be described in more detail with reference to examples.

[Examples corresponding to the first manufacturing method]
<Example 1>
1. Preparation of inorganic molded body (1) Raw material As raw material powder, a 0.8 mm sieve passage of ALC cutting powder was used. Although the data are not shown in detail, this ALC cutting powder has a CaO / SiO ₂ ratio of 0.45 and was confirmed to contain tobermorite by powder X-ray diffraction analysis.
A silver nitrate special grade reagent (Yoneyama Chemical Co., Ltd.) was used as a salt containing an antibacterial and antifungal deodorant metal ion.

(2) Preparation of inorganic molded body 35 parts by weight of an aqueous silver nitrate solution was added to 100 parts by weight of ALC cutting powder and stirred. The silver nitrate concentration in the aqueous solution is 0.005% by weight in terms of the weight of silver ions in the target inorganic molded body (the weight of silver relative to the total weight of the inorganic molded body) in view of the weight increase due to the subsequent carbonation treatment. % Was adjusted.
The obtained kneaded material was filled into a 300 mm × 300 mm mold, and then press-molded to a thickness of 8 mm at a pressure of 20 MPa.
Subsequently, the obtained molded product was carbonized. The molded product was put in a sealed container, and the inside of the container was deaerated with a vacuum pump. Then, a commercially available carbon dioxide gas having a purity of 99.5% was introduced into the container until the pressure became 0.2 MPa, and the initial temperature was 25 ° C. The carbonation reaction was carried out while maintaining the time to obtain the desired inorganic molded body.

2. Test (1) Analysis The obtained inorganic molded body was pulverized with an agate mortar and analyzed by a powder X-ray diffraction method.
The specific surface area and pore size distribution of the inorganic molded body were measured by a nitrogen adsorption method using Micromeritex Asap 2400 (manufactured by Shimadzu Corporation).
The bulk density was measured according to JIS A 5416.
The supporting rate of silver in the inorganic molded body was determined by the following formula (1) from the total weight of the inorganic molded body and the weight of silver.
Support rate (% by weight) = silver weight / total weight of inorganic molded body (1)

(2) Humidity adjustment test The moisture conductivity was measured according to JIS A 1470-1 “Moisture absorption and desorption test” in the middle humidity range according to JIS A 1324.

(3) Strength The inorganic molded body was cut into 100 mm × 25 mm × 8 mm to obtain a test piece, and the bending strength was measured in accordance with JIS A 5209.

(4) Deodorization test The obtained inorganic molded body was cut into 100 mm x 100 mm x 8 mm and used as a test piece. One of the front and back surfaces of the test piece was left, the other surface and the side surface were covered with an aluminum seal, and the test piece was left under an atmosphere of 20 ° C. and a humidity of 50% until there was no change in weight.
Next, the test piece was placed in a 100 liter stainless steel chamber to be sealed, and an experimental standard gas of hydrogen sulfide diluted to 0.3 ppm with nitrogen gas was injected while maintaining the temperature in the chamber at 20 ° C. . The time of injection was set as the test start time, and the hydrogen sulfide gas concentration in the chamber was measured every predetermined time after the test started. Also, 2 hours after the start of the test, the temperature inside the chamber was raised to 35 ° C., and it was confirmed whether or not the hydrogen sulfide gas concentration in the chamber had increased.
Moreover, it replaced with hydrogen sulfide and tested similarly using methyl mercaptan and ammonia gas. The initial concentration was 1 ppm methyl mercaptan and 5 ppm ammonia gas.

(5) Antibacterial test, fungus resistance test An antibacterial test was conducted according to JIS Z 2801. Staphylococcus aureus and Escherichia coli were used as test bacteria, and the results of both were comprehensively judged.
The mold resistance test was conducted according to JIS Z 2911. As mold for the test, Aspergillus niger was used.

<Example 2>
An inorganic molded body was prepared and tested in the same manner as in Example 1 except that the silver nitrate concentration of the aqueous solution was adjusted so that the silver loading was 0.1%.

<Example 3>
An inorganic molded body was prepared and tested in the same manner as in Example 1 except that the silver nitrate concentration in the aqueous solution was adjusted so that the silver loading was 0.5%.

[Example group corresponding to the second manufacturing method]
<Example 4>
Water was added to 100 parts by weight of ALC cutting powder as a raw material powder to form a slurry of 300 parts by weight, and the mixture was stirred and deaerated while maintaining at 50 ° C. Next, 100 parts by weight of an aqueous silver nitrate solution was added to the slurry, and ion exchange was performed by stirring for 18 hours while maintaining the temperature at 50 ° C. to obtain a silver-carrying ALC cutting powder (hereinafter referred to as “silver-carrying raw material powder”). . In addition, the silver nitrate concentration of the aqueous solution was adjusted so that the supporting rate of silver ions in the target inorganic molded body was 0.05% by weight in view of the weight increase due to the subsequent carbonation treatment.
The obtained silver-supporting raw material powder was washed with distilled water, filtered and dried.
Using the silver-supported raw material powder after drying, it was molded and carbonized in the same manner as in Example 1 to obtain an inorganic molded body. The obtained inorganic molded body was tested in the same manner as in Example 1.

<Example 5>
An inorganic compact was prepared and tested in the same manner as in Example 4 except that the silver nitrate concentration in the aqueous solution was adjusted so that the silver loading was 0.1%.

<Example 6>
An inorganic molded body was prepared and tested in the same manner as in Example 4 except that the silver nitrate concentration of the aqueous solution was adjusted so that the silver loading was 0.5%.

[Example group-1 corresponding to the third production method]
<Example 7>
The same ALC cutting powder as the raw material powder is used as the carrier powder, and a 0.2N silver nitrate aqueous solution is used to perform ion exchange in the same ion exchange operation as in Example 4, thereby carrying the silver-carrying ALC cutting powder. (Hereinafter referred to as “silver-supported powder”). The amount of silver supported per unit weight of the silver-supported powder was measured and found to be 18.9 mg / g.
The obtained silver-supported powder was added to 100 parts by weight of ALC cutting powder (raw material powder) on which silver was not supported to obtain a mixed powder. The amount of silver-supported powder added is such that the silver-supported amount of the silver-supported powder is 0.0025% by weight in consideration of the silver-supported amount of this silver-supported powder and the subsequent weight increase due to carbonation treatment. Adjusted.
35 parts by weight of water was added to 100 parts by weight of this mixed powder and stirred, and then molded and carbonized in the same manner as in Example 1 to obtain an inorganic molded body. The obtained inorganic molded body was tested in the same manner as in Example 1.

<Example 8>
An inorganic molded body was prepared and tested in the same manner as in Example 7 except that the addition amount of the silver-supported powder was adjusted so that the silver support rate was 0.005%.

<Example 9>
An inorganic molded body was prepared and tested in the same manner as in Example 7 except that the addition amount of the silver-supported powder was adjusted so that the silver support ratio was 0.1%.

<Example 10>
An inorganic molded body was prepared and tested in the same manner as in Example 7 except that the addition amount of the silver-supported powder was adjusted so that the silver support ratio was 0.5%.

[Example group-2 corresponding to the third production method]
<Example 11>
After adding water to the same ALC cutting powder as the raw material powder, it is treated under the same conditions as in the carbonation treatment of Example 1, and is mainly composed of calcium carbonate and amorphous silica originating from tobermorite. A powder was obtained.
The obtained granular material was used as a carrier powder, and a silver-supported powder was prepared in the same manner as in Example 7. The amount of silver supported per unit weight of this silver-supported powder was measured and found to be 11.7 mg / g. Using this silver-supported powder, an inorganic molded body was prepared and tested in the same manner as in Example 7. The addition amount of the silver-supported powder was adjusted so that the silver support rate of the target inorganic molded body was 0.005% by weight.

<Example 12>
An inorganic molded body was prepared and tested in the same manner as in Example 11 except that the addition amount of the silver-supported powder was adjusted so that the silver support ratio was 0.1%.

<Example 13>
An inorganic molded body was prepared and tested in the same manner as in Example 11 except that the addition amount of the silver-supported powder was adjusted so that the silver support ratio was 0.5%.

<Comparative example>
35 parts by weight of water was added to 100 parts by weight of ALC cutting powder, and the mixture was stirred and molded and carbonized in the same manner as in Example 1 to obtain an inorganic molded body. The obtained inorganic molded body was tested in the same manner as in Example 1.

[Results and discussion]
Regarding Examples 1 to 13 and Comparative Examples, the composition and physical properties of the obtained inorganic molded bodies are shown in Table 1, and the results of the antibacterial test, mold resistance test and deodorization test are shown in Table 2. FIG. 4 is a graph showing the pore size distribution of the inorganic molded body obtained in Example 1.

1. Physical Properties Regarding the inorganic molded bodies of Examples 1 to 13 and Comparative Example, powder X-ray diffraction confirmed vaterite calcite, which is calcium carbonate, and clear peaks of crystalline silica. Further, a broad peak at 2θ = 20 to 30 ° indicating the presence of amorphous silica was confirmed.

  As shown in FIG. 4, the inorganic molded body of Example 1 had peaks in the pore diameter regions of about 100 nm and 3 nm or less, respectively. Moreover, although data is not shown in detail, the inorganic molded bodies of other examples and comparative examples also showed the same pore size distribution as that of Example 1. Meso-micropores having a pore diameter of 3 nm or less serve to increase the specific surface area and increase the moisture absorption / release amount. On the other hand, macropores having a pore diameter of about 100 nm serve to increase moisture conductivity. In the inorganic molded body of this example, high humidity control is realized by the synergistic effect of both.

  Regarding the bending strength, it was confirmed that the specimens of Examples 1 to 10 had a bending strength of 4 MPa and sufficient strength for use as a building material. On the other hand, in Examples 11 to 13, the bending strength was slightly reduced as compared with other Examples. In these examples, carbonized ALC cutting powder is used as the carrier powder, and this carbonized body does not have hydraulic properties or carbonic curability, and thus the strength of the molded body can be expressed. Since it does not contribute, it is thought that the strength of the molded body is reduced. However, the decrease in strength is considered to correlate with the added amount of the carrier powder, and if the added amount of the carrier powder is small, it is considered that a molded body that can withstand use as a building material can be manufactured.

In Examples 4 to 6, the silver loadings were 0.06, 0.12, and 0.42% by weight, respectively, and from the set values of 0.05, 0.1, and 0.5% by weight, a little There was a change. In this way, in the second production method, silver ions are washed away from the silver-supported powder by the washing and filtering operation after the ion exchange is completed, so the amount of silver ions added in the ion-exchange process and the silver support rate of the inorganic compact The correlation with is slightly reduced.
On the other hand, in Examples 1 to 3 (first manufacturing method), there is no washing and filtration step, and since there is almost no loss of silver ions in the carbonation step, almost all of the silver ions added in the kneading step. The entire amount remains in the molded body. Moreover, in Examples 7-13, the silver carrying amount of the silver carrying powder after completion | finish of washing | cleaning filtration operation was measured, and the addition amount of the silver carrying powder to the raw material powder in a kneading process was determined based on the value. In addition, since there is almost no loss of silver ions in the subsequent carbonation step, almost the entire amount of silver ions added in the kneading step remains in the molded body. For this reason, it was possible to control the silver loading of the inorganic molded body to a target value.

2. Antibacterial Test From Table 2, in Examples 1 to 13, a decrease in the number of bacteria was observed, and antibacterial properties were confirmed. In particular, in Examples 1 to 6 and Examples 8 to 13 having a silver loading of 0.005% by weight or more, both S. aureus and E. coli were below the lower detection limit, and the antibacterial effect was confirmed. Specifically, in the test sample of Example 8, the inoculum of Staphylococcus aureus with 1.7 × 10 ⁵ bacteria number decreased to 10 or less after 24 hours at a storage temperature of 35 ° C. . In addition, the number of bacteria inoculated with 4.5 × 10 ⁵ was similarly reduced to 10 or less. On the other hand, in Example 7 with a silver loading of 0.0025% by weight, the numbers of both Staphylococcus aureus and Escherichia coli were significantly reduced, but detection was possible. This is presumably because the amount of silver added contributing to antibacterial properties was small.
On the other hand, in Comparative Example 1, no decrease in the number of bacteria was observed in both S. aureus and E. coli, and no antibacterial activity was observed.

3. Mold Resistance Test From Table 2, in Examples 1 to 13, mycelial growth was not observed with the naked eye and further under a microscope, and mold resistance was confirmed. On the other hand, in Comparative Example 1 containing no silver, the growth of mycelia was not recognized with the naked eye, but the presence of mycelia was confirmed with a microscope.

4). Deodorization Test From Table 2, in Examples 1 to 13, when tested using hydrogen sulfide and ammonia as odor components, the concentration half-life (necessary for the odor component concentration to be reduced to half the initial concentration). ) Was 5 minutes to 15 minutes, and an abrupt decrease in odor concentration was observed immediately after the start of the test. Even when methyl mercaptan was used as the odor component, the concentration half-life was about 5 to 30 minutes, and in Example 7 with the lowest silver loading rate, it was 60 minutes. The rapid decrease in the concentration of the odor component immediately after the start of the test is considered to be because the odor component was quickly taken into the pores of the inorganic molded body due to the presence of the macropores, and in particular, the molecular weight was small. It is thought that the effect was large against hydrogen sulfide and ammonia. In addition, although data is not described in detail, in any of the examples, the odor concentration almost reached the detection limit within 2 hours when any odor component was used.

  Also, no increase in the concentration of odor components due to the temperature rise after 2 hours was observed. The fact that no increase in the concentration of the odor component due to temperature rise was observed is considered to indicate that the odor component was not simply physically adsorbed but decomposed by the action of silver.

  On the other hand, in the comparative example not supporting silver, when the odor component was ammonia, a decrease in the odor concentration was observed in the same manner as in the example, but for hydrogen sulfide and methyl mercaptan, 120 minutes passed. Even after that, the concentration could not be reduced below the half-value. Moreover, when the temperature was raised, the concentration of the odor component was increased. This is considered to be because the odor component once adsorbed by the temperature rise was released because the odor component was merely physically adsorbed to the pores and not subjected to the action of decomposition or the like.

Process diagram of the first manufacturing method Process diagram of the second manufacturing method Process diagram of the third manufacturing method The graph showing the pore size distribution of the inorganic molded body obtained in Example 1

Claims (10)

An inorganic molded body mainly composed of calcium carbonate and amorphous silica originating from a calcium silicate compound,
The specific surface area measured by the nitrogen gas adsorption method is 80 m ² / g or more and 250 m ² / g or less,
Having a pore size distribution in which a peak exists in each of a region having a diameter of 5 nm or less and a region having a diameter of 50 nm to 1000 nm,
And the inorganic molded object characterized by carrying | supporting the ion of an antibacterial anti-fungal deodorant metal to the said calcium carbonate or the said amorphous silica.   The inorganic molded body according to claim 1, wherein the calcium carbonate contains vaterite.   3. The antibacterial / antifungal deodorant metal loading rate is 0.005% by weight or more and 0.5% by weight or less based on the total weight of the inorganic molded body. An inorganic molded article according to any one of the above.   The inorganic molded body according to any one of claims 1 to 3, wherein the antibacterial and antifungal deodorant metal is at least one selected from the group consisting of silver, copper, and zinc. Inorganic molding mainly composed of calcium carbonate and amorphous silica originating from a calcium silicate compound, wherein the calcium carbonate or the amorphous silica carries an antibacterial, antifungal and deodorant metal ion A method of manufacturing a body,
A kneading step of mixing an aqueous solution containing ions of the antibacterial and antifungal deodorant metal with a raw material powder mainly composed of a calcium silicate compound;
A molding step for molding the kneaded product obtained in the kneading step;
And a carbonation treatment step of curing the molded product obtained in the molding step in a carbon dioxide gas atmosphere.   In the kneading step, the concentration of the antibacterial and antifungal deodorant metal contained in the aqueous solution is 0.01 wt% or more and 5.0 wt% or less, and the addition ratio of the aqueous solution to the raw material powder is It is 10 to 50 weight% with respect to the dry weight of raw material powder, The manufacturing method of the inorganic molded object of Claim 5 characterized by the above-mentioned. Inorganic molding mainly composed of calcium carbonate and amorphous silica originating from a calcium silicate compound, wherein the calcium carbonate or the amorphous silica carries an antibacterial, antifungal and deodorant metal ion A method of manufacturing a body,
An aqueous solution containing the antibacterial and antifungal deodorant metal ions is mixed with a raw material powder mainly composed of a calcium silicate compound, and at least a part of the calcium ions contained in the calcium silicate compound is mixed with the antibacterial and antifungal deodorant. An ion exchange step for obtaining a metal-supported raw material powder by substituting with ions of a conductive metal;
A washing step of washing the obtained metal-supporting raw material powder;
A moisture content adjusting step of adjusting the moisture content of the metal-supporting raw material powder after the washing step;
A molding step for molding the metal-supporting raw material powder after the moisture content adjustment step is completed;
And a carbonation treatment step of curing the molded product obtained in the molding step in a carbon dioxide gas atmosphere. Inorganic molding mainly composed of calcium carbonate and amorphous silica originating from a calcium silicate compound, wherein the calcium carbonate or the amorphous silica carries an antibacterial, antifungal and deodorant metal ion A method of manufacturing a body,
An aqueous solution containing the antibacterial and antifungal deodorant metal ions is mixed with a carrier powder mainly composed of a calcium silicate compound, and at least a part of the calcium ions contained in the calcium silicate compound is mixed with the antibacterial and antifungal agent. An ion exchange step of obtaining metal-supported powder by substituting with ions of odorous metal,
A washing and drying step of washing the obtained metal-supported powder and then drying;
A kneading step of adding and mixing the metal-supported powder and water after washing and drying to a raw material powder mainly composed of a calcium silicate compound;
A molding step for molding the kneaded product obtained in the kneading step;
And a carbonation treatment step of curing the molded product obtained in the molding step in a carbon dioxide gas atmosphere. Inorganic molding mainly composed of calcium carbonate and amorphous silica originating from a calcium silicate compound, wherein the calcium carbonate or the amorphous silica carries an antibacterial, antifungal and deodorant metal ion A method of manufacturing a body,
An aqueous solution containing ions of the antibacterial and antifungal deodorant metal is mixed with a carrier powder mainly composed of calcium carbonate and amorphous silica originating from a calcium silicate compound to form the calcium silicate compound. An ion exchange step of obtaining a metal-supported powder by substituting at least a part of the contained calcium ions with ions of the antibacterial and antifungal deodorant metal;
A washing and drying step of washing the obtained metal-supported powder and then drying;
A kneading step of adding and mixing the metal-supported powder and water after washing and drying to a raw material powder mainly composed of a calcium silicate compound;
A molding step for molding the kneaded product obtained in the kneading step;
And a carbonation treatment step of curing the molded product obtained in the molding step in a carbon dioxide gas atmosphere.   The said raw material powder is a lightweight aerated concrete powder, The manufacturing method of the inorganic molded object in any one of Claims 5-9 characterized by the above-mentioned.

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